Indecorum

Want of decorum; impropriety of behavior; that in behavior or manners which violates the established rules of civility, custom, or etiquette; indecorousness.

2.

An indecorous or becoming action.

Young.

Syn. -- Indecorum is sometimes synonymous with indecency; but indecency, more frequently than indecorum, is applied to words or actions which refer to what nature and propriety require to be concealed or suppressed. Indecency is the stronger word; indecorum refers to any transgression of etiquette or civility, especially in public.